Dielectric composition and multilayer electronic component including the same

ABSTRACT

A dielectric composition includes one of BaTiO3, (Ba,Ca)(Ti,Ca)O3, (Ba,Ca)(Ti,Zr)O3, Ba(Ti,Zr)O3 and (Ba,Ca)(Ti,Sn)O3, as a main component, a first subcomponent including a rare earth element, and a second subcomponent including at least one of a variable valence acceptor element and a fixed valence acceptor element. When a sum of contents of the rare earth element is defined as DT and a sum of contents of the variable valence acceptor element and the fixed valence acceptor element is defined as AT, (DT/AT)/(Ba+Ca) satisfies more than 0.5 and less than 6.0. In addition, a multilayer electronic component including the dielectric composition is provided.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is the continuation application of U.S. patentapplication Ser. No. 16/842,388 filed Apr. 7, 2020, which claims thebenefit under 35 USC 119(a) of Korean Patent Application No.10-2019-0115901 filed on Sep. 20, 2019 in the Korean IntellectualProperty Office, the entire disclosures of which are incorporated hereinby reference for all purposes.

BACKGROUND 1. Field

The present disclosure relates to a dielectric composition and amultilayer electronic component including the same.

2. Description of Related Art

In general, electronic components using a ceramic material, such ascapacitors, inductors, piezoelectric elements, varistors, orthermistors, include a ceramic body formed of a ceramic material, aninternal electrode formed inside the body, and an external electrodedisposed on the surface of the ceramic body to be connected to theinternal electrode.

Recently, as electronic products have become smaller and moremultifunctional, chip components have become smaller and higher infunctionality. Therefore, as multilayer ceramic capacitors (MLCCs) asmultilayer electronic components, smallsized and high-capacity productshave also been required.

To obtain miniaturization and high capacity of multilayer ceramiccapacitors at the same time, a large number of layers are laminated byreducing the thicknesses of the dielectric layer and the electrode layertherein, and at present, the thickness of a dielectric layer is about0.6 μm, and the development of dielectric layers with further reducedthicknesses continues.

Due to the trend for higher levels of capacitance and ultra-thin layersin multilayer ceramic capacitors, it is essential to design compositionsfor multilayer ceramic capacitors having high dielectric constants.

In such a situation, securing the reliability of the dielectric layerhas emerged as an important issue of dielectric materials, and also, itis an important problem that quality and yield management are difficultdue to an increase in dielectric insulation resistance deterioration.

To solve this problem, there is a need for a new method for securinghigh reliability not only in the structural aspect of the multilayerceramic capacitor but also in terms of the composition of dielectric.

In general, in the related art to secure high dielectric properties, ahigh dielectric constant is secured by simply causing the grain growthto adjust the number of dipoles in a crystal. However, according to therelated art, the capacitance change rate depending on temperature and DCvoltage increases when designing a high dielectric constant compositionby grain growth, and problems such as a decrease in reliability due to adecrease in the number of particles per dielectric layer may occur atthe same time.

Therefore, to manufacture a dielectric composition in which a capacityreduction rate according to DC voltage is not increased, whileimplementing high dielectric properties without deterioration ofreliability even in a case in which the dielectric layer is thinned; amethod of increasing the dielectric constant without accompanying graingrowth is required.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

An aspect of the present disclosure is to provide a dielectriccomposition capable of improving reliability and a multilayer electroniccomponent including the same.

An aspect of the present disclosure is to provide a dielectriccomposition capable of improving a dielectric constant and a multilayerelectronic component including the same.

An aspect of the present disclosure is to provide a dielectriccomposition capable of significantly reducing a decrease in withstandvoltage, while having a thin dielectric layer, and a multilayerelectronic component including the same.

According to an aspect of the present disclosure, a dielectriccomposition includes one of BaTiO₃, (Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃,Ba(Ti,Zr)O₃ and (Ba,Ca)(Ti,Sn)O₃, as a main component, a firstsubcomponent including a rare earth element, and a second subcomponentincluding at least one of a variable valence acceptor element and afixed valence acceptor element. When a sum of contents of the rare earthelement is defined as DT and a sum of contents of the variable valenceacceptor element and the fixed valence acceptor element is defined asAT, (DT/AT)/(Ba+Ca) satisfies more than 0.5 and less than 6.0.

According to an aspect of the present disclosure, a multilayerelectronic component includes a body including a dielectric layer and aninternal electrode, and an external electrode disposed on the body andconnected to the internal electrode. The dielectric layer includes adielectric composition. The dielectric composition includes one ofBaTiO₃, (Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃, Ba(Ti,Zr)O₃ and(Ba,Ca)(Ti,Sn)O₃, as a main component, a first subcomponent comprising arare earth element, and a second subcomponent comprising at least one ofa variable valence acceptor element and a fixed valence acceptorelement. When a sum of contents of the rare earth element is defined asDT, and a sum of contents of the variable valence acceptor element andthe fixed valence acceptor element is defined as AT, (DT/AT)/(Ba+Ca)satisfies more than 0.5 and less than 6.0.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 schematically illustrates a perspective view of a multilayerelectronic component according to an embodiment of the presentdisclosure;

FIG. 2 is a schematic cross-sectional view taken along line I-I′ of FIG.1;

FIG. 3 schematically illustrates a cross-sectional view taken along lineII-II′ of FIG. 1;

FIG. 4 is an exploded perspective view schematically illustrating a bodyin which a dielectric layer and an internal electrode are stackedaccording to an embodiment of the present disclosure;

FIG. 5 is an image provided by capturing crystal grains of a dielectriclayer formed using a dielectric composition in which La and Dy are addedas a rare earth element; and

FIG. 6 is an image provided by capturing crystal grains of a dielectriclayer formed using a dielectric composition in which only Dy is added asa rare earth element.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there may be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as illustrated in the figures. Suchspatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, an element described as being “above” or “upper”relative to another element will then be “below” or “lower” relative tothe other element. Thus, the term “above” encompasses both the above andbelow orientations depending on the spatial orientation of the device.The device may also be oriented in other ways (for example, rotated 90degrees or at other orientations), and the spatially relative terms usedherein are to be interpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof

Due to manufacturing techniques and/or tolerances, variations of theshapes illustrated in the drawings may occur. Thus, the examplesdescribed herein are not limited to the specific shapes illustrated inthe drawings, but include changes in shape that occur duringmanufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

The drawings may not be to scale, and the relative size, proportions,and depiction of elements in the drawings may be exaggerated forclarity, illustration, and convenience.

Subsequently, examples are described in further detail with reference tothe accompanying drawings.

In the drawings, the X direction may be defined as the second direction,L direction or length direction, the Y direction may be defined as thethird direction, W direction or width direction; and the Z direction maybe defined as the first direction, stacking direction, T direction, orthickness direction.

Dielectric Composition

A dielectric composition according to an embodiment includes one ofBaTiO₃, (Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃, Ba(Ti,Zr)O₃ and(Ba,Ca)(Ti,Sn)O₃, as a main component, a first subcomponent comprising arare earth element, and a second subcomponent comprising at least one ofa variable valence acceptor element and a fixed valence acceptorelement. In this case, when the sum of the rare earth element contentsis defined as DT and the sum of the valence variable acceptor elementand fixed valence acceptor element contents is defined as AT,(DT/AT)/(Ba+Ca) satisfies more than 0.5 and less than 6.0.

Due to the trend toward higher capacities and ultra-thin layers ofmultilayer ceramic capacitors, it is essential to design a compositionfor a multilayer ceramic capacitor having a high dielectric constant.

In general, in the related art for securing high dielectric properties,a high dielectric constant is secured by controlling the number ofdipoles in the crystal by simply causing the growth of the particle.However, according to the related art, in designing a high dielectricconstant composition by particle growth, the capacity change rateaccording to temperature and DC voltage increases, and problems such asa decrease in reliability due to a decrease in the number of particlesper dielectric layer may occur at the same time.

To manufacture a dielectric composition in which high dielectricproperties may be implemented without deterioration of reliability and acapacity reduction rate due to DC voltage does not increase even in thecase in which the dielectric layer is thinned, a method of increasingthe dielectric constant without accompanying grain growth is required.

In embodiments of the present disclosure, by controlling the correlationbetween the rare earth element content, the acceptor element and fixedvalence acceptor element contents, and barium (Ba) and calcium (Ca)contents, contained in the dielectric composition; high dielectricconstant and high reliability may be both obtained by intentionally,slightly increasing the current density and reducing the oxygen vacancydefect generation concentration, thereby improving insulation resistanceand a dielectric constant per grain size. In addition, a dielectriccomposition without the reduction in aging characteristics, DC electricfield dependency, and the like may be provided.

The main components, BaTiO₃, (Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃,Ba(Ti,Zr)O₃, and (Ba,Ca)(Ti,Sn)O₃, have the perovskite structurerepresented by ABO₃, in which oxygen vacancies may occur, in which theplace where oxygen should be present is empty. For example, oxygenvacancy may occur when firing is performed in a reducing atmosphere, andoxygen vacancy may occur when carbon is evaporated in the form of CO₂ bycombining with oxygen of ABO₃ by debinder or the like.

For example, O has a charge of −2, and if the place where oxygen shouldbe present is empty, oxygen vacancies with a charge of +2 occur, andwhen oxygen vacancies are moved by an applied electric field,reliability is lowered. In addition, in this case, as oxygen vacanciesincrease, and the higher the temperature and voltage, the higher themoving speed and the moving amount, further worsening the reliability.

To solve the problem of oxygen vacancies, in general, a method ofimproving reliability by reducing the concentration of oxygen vacanciesby adding rare earth elements is known. However, there has been aproblem in which the dielectric constant per grain size is lowered orthe insulation resistance is lowered due to excessivesemiconductorization.

Thus, in examples of the present disclosure, when the sum of the contentof the rare earth element content is DT, and the sum of the contents ofthe variable valence acceptor element and the fixed valence acceptorelement is defined as AT, (DT/AT)/(Ba+Ca) may be greater than 0.5 andless than 6.0, thereby improving the dielectric constant per grain sizeto ensure high dielectric properties while significantly reducing graingrowth, and thus, securing insulation resistance.

If a value ((DT/AT)/(Ba+Ca)) obtained by dividing the ratio (DT/AT) ofthe sum (DT) of the rare earth element contents to the sum (AT) of thecontents of the variable valence acceptor element and the fixed valenceacceptor element by the sum (Ba+Ca) of Ba content and Ca content, is 0.5or less, the dielectric constant per grain size may be relatively low.Therefore, the (DT/AT)/(Ba+Ca) may be more than 0.5, in more detail, 0.7or more, in further detail, 1.0 or more.

If (DT/AT)/(Ba+Ca) is 6.0 or more, there is a fear that the insulationresistance may decrease as the charge density increases. In addition,due to increase of the concentration and the generation of theelectronic charge carrier represented by the following defect rateformula, the electrical conductivity in the dielectric layer of themultilayer ceramic capacitor may increase rapidly, thereby causing theproblem in that the reduction resistance is lowered.

RE₂O₃2TiO₂→2RE*_(Ba)+2Ti_(Ti)+60 _(O)½O₂+2e  Defect Rate Formula

Therefore, (DT/AT)/(Ba+Ca) is, in detail, less than 6.0, in more detail5.5 or less, in further detail 5.0 or less.

In this case, the rare earth element includes lanthanum (La), andfurther includes at least one of yttrium (Y), actinium (Ac), cerium(Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm),europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium(Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and ruthenium (Lu), andthe content ratio (La/DT) of the lanthanum (La) to the sum (DT) of therare earth element contents may satisfy 0.1 or more and less than 1.0.

Lanthanum (La) may effectively replace the Ba site, and is thus moreeffective in reducing the oxygen vacancies defect concentration, and mayserve to suppress grain growth.

If La/DT is less than 0.1, the lanthanum addition effect may beinsufficient. Therefore, La/DT may be 0.1 or more. To more reliablysecure the effect of adding lanthanum (La), La/DT may be greater than0.1, and in further detail, may be 0.2 or more.

On the other hand, if La/DT is 1.0, the insulation resistance maydecrease as the charge density increases, and the electricalconductivity in the dielectric layer of the multilayer ceramic capacitorrapidly increases due to the generation and increased concentration ofthe electronic charge carrier, and thus, a problem of deterioration inreduction resistance may occur. Accordingly, La/DT may be less than 1.0,in more detail, 0.9 or less, in further detail, 0.8 or less.

FIG. 5 is an image provided by capturing crystal grains of a dielectriclayer formed using a dielectric composition in which La and Dy are addedas a rare earth element.

FIG. 6 is an image provided by capturing crystal grains of a dielectriclayer formed using a dielectric composition in which only Dy is added asa rare earth element.

Referring to FIGS. 5 and 6, it can be seen that the grains of thedielectric layer formed by using the dielectric composition in which Laand Dy are added are smaller than when only Dy is added.

The dielectric layer of FIG. 5 has a dielectric constant (ε) of 3240 andthe dielectric layer of FIG. 6 has a dielectric constant (ε) of 2430.Therefore, it can be confirmed that the dielectric constant per grainsize of the dielectric layer formed using the dielectric composition inwhich La and Dy are added is higher than when only Dy is added.

Hereinafter, each component of the dielectric composition according toan embodiment will be described in detail.

a) Main Component

A dielectric composition according to an embodiment includes one ofBaTiO₃, (Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃, Ba(Ti,Zr)O₃ and(Ba,Ca)(Ti,Sn)O₃, as a main component.

In a more detailed example, the dielectric composition may include atleast one selected from the group consisting of BaTiO₃,(Ba_(1-x)Ca_(x))(Ti_(1-y)Ca_(y))O₃ (where x is 0≤x≤0.3 and y is0≤y≤0.1), (Ba_(1-x)Ca_(x))(Ti_(1-y)Zr_(y))O₃ (where x is 0≤x≤0.3 and yis 0≤y≤0.5), Ba(Ti_(1-y)Zr_(y))O₃ (0<y≤0.5) and(Ba_(1-x)Ca_(x))(Ti_(1-y)Sn_(y))O₃ (where x is 0≤x≤0.3 and y is0≤y≤0.1).

A dielectric composition according to an embodiment may have a roomtemperature dielectric constant of 2000 or more.

The main component is not particularly limited, but the average particlediameter of the main component powder may be 40 nm or more and 200 nm orless.

b) First Subcomponent

According to an embodiment of the present disclosure, the dielectriccomposition includes a first subcomponent comprising a rare earthelement.

The rare earth element replaces the A-site of the ABO₃ structure andserves as a donor, thereby reducing the concentration of oxygenvacancies and thus improving reliability. In addition, the rare earthelement acts as a barrier to prevent the flow of electrons at the grainboundary, thereby suppressing an increase in leakage current.

In this case, the first subcomponent may include 0.2 mole or more and4.0 moles or less of an oxide or carbonate containing the rare earthelement, relative to 100 moles of the main component.

If the content of the oxide or carbonate containing the rare earthelement is less than 0.2 mol relative to 100 moles of the maincomponent, the above-described effects may be insufficient.

On the other hand, as the rare earth element content increases, it isadvantageous in terms of reliability improvement. However, if thecontent of the oxide or carbonate containing the rare earth element ismore than 4.0 moles relative to 100 moles of the main component, thecharacteristics of the insulator and sinterability may decrease due tosemiconductorization.

c) Second Subcomponent

According to an embodiment, the dielectric composition includes a secondsubcomponent comprising at least one of a variable valence acceptorelement and a fixed valence acceptor element.

The variable valence acceptor element and the fixed valence acceptorelement mainly act as acceptors by substituting the B-site of the ABO₃structure, and may serve to reduce the electron concentration, and thus,may serve to suppress semiconductorization of the dielectric layer byA-site solid solution of a rare earth element. In addition, the variablevalence acceptor element and the fixed valence acceptor element mayserve to lower the firing temperature and improve the high temperaturewithstand voltage characteristics of the multilayer ceramic capacitor towhich the dielectric composition is applied.

To this end, as described above, when the sum of the rare earth elementcontents is defined as DT, and the sum of the variable valence acceptorelement and the fixed valence acceptor element contents is defined asAT, (DT/AT)/(Ba+Ca) may satisfy 0.5 or more and less than 6.0 by addingone or more of the variable valence acceptor element and the fixedvalence acceptor element. Thus, the dielectric constant per grain sizemay be improved to ensure high dielectric properties while significantlyreducing grain growth.

In this case, the variable valence acceptor element may include at leastone of manganese (Mn), vanadium (V), chromium (Cr), iron (Fe), nickel(Ni), cobalt (Co), copper (Cu) and zinc (Zn), and the fixed valenceacceptor element includes at least one of magnesium (Mg) and zirconium(Zr).

In addition, the second subcomponent may include 0.01 mole or more and4.0 moles or less of an oxide or carbonate containing one or more of thevariable valence acceptor element and the fixed valence acceptorelement, relative to 100 moles of the main component.

If the oxide or carbonate containing at least one of the variablevalence acceptor element and the fixed valence acceptor element is lessthan 0.01 mol relative to 100 moles of the main component, it may bedifficult to suppress the semiconductorization of the dielectric layerdue to the addition of the rare earth element, and there is apossibility that the firing temperature may be increased and the hightemperature withstand voltage characteristics are slightly lowered.

On the other hand, if the oxide or carbonate containing one or more ofthe variable valence acceptor element and the fixed valence acceptorelement is more than 4.0 moles relative to 100 moles of the maincomponent, the breakdown voltage (BDV) or room temperature specificresistance may decrease.

c) Third Subcomponent

According to an embodiment of the present disclosure, the dielectriccomposition may include a third subcomponent which is an oxide orcarbonate containing Ba, and the third subcomponent may be included inan amount of 0.37 mol or more and 4.0 mol or less with respect to 100mol of the main component.

The content of the third subcomponent may be based on the content of Baelement included in the third subcomponent without distinguishing anaddition form such as an oxide or a carbonate.

The third subcomponent may serve to promote sintering, control adielectric constant, and the like, in the dielectric ceramiccomposition, and if the content of the third subcomponent is less than0.37 mole with respect to 100 moles of the main component, the effectmay be insufficient. If exceeding 4.0 moles, there may be a problem inwhich the dielectric constant is lowered or the firing temperature isincreased.

d) Fourth Subcomponent

According to an embodiment of the present disclosure, the dielectriccomposition includes, as a fourth subcomponent, at least one of an oxideincluding at least one of Si and Al and a glass compound including Si,and the fourth subcomponent may be included in an amount of 0.5 mol ormore and 7.0 mol or less with respect to 100 mol of the main component.

The content of the fourth subcomponent may be based on the content of atleast one or more elements among Si and Al included in the fourthsubcomponent without distinguishing an addition form such as glass,oxide, or carbonate.

The fourth subcomponent serves to lower the firing temperature and thehigh temperature withstand voltage characteristics of the multilayerceramic capacitor to which the dielectric composition is applied.

If the content of the fourth subcomponent is less than 0.5 mole withrespect to 100 moles of the main component, the effect may beinsufficient. If the content of the fourth subcomponent is more than 7.0moles, there may be problems such as lowering of sinterability anddensity, and secondary phase generation.

Multilayer Electronic Component

FIG. 1 schematically illustrates a perspective view of a multilayerelectronic component according to an embodiment of the presentdisclosure.

FIG. 2 is a schematic cross-sectional view taken along line I-I′ of FIG.1.

FIG. 3 schematically illustrates a cross-sectional view taken along lineII-II′of FIG. 1.

FIG. 4 is an exploded perspective view schematically illustrating a bodyin which a dielectric layer and an internal electrode are stackedaccording to an embodiment of the present disclosure.

Referring to FIGS. 1 to 4, a multilayer electronic component 100according to an embodiment may include a body 110 including a dielectriclayer 111 and internal electrodes 121 and 122; and external electrodes131 and 132 disposed on the body 110 and connected to the internalelectrodes 121 and 122. The dielectric layer 111 includes a dielectriccomposition. The dielectric composition includes one of BaTiO₃,(Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃, Ba(Ti,Zr)O₃ and (Ba,Ca)(Ti,Sn)O₃, asa main component; a first subcomponent comprising a rare earth element;and a second subcomponent comprising at least one of a variable valenceacceptor element and a fixed valence acceptor element. In this case,when the sum of the rare earth element contents is defined as DT, thesum of the variable valence acceptor element and fixed valence acceptorelement contents is defined as AT, (DT/AT)/(Ba+Ca) satisfies more than0.5 and less than 6.0.

Hereinafter, the descriptions of the configurations overlapping withthose described in the above-described dielectric composition will beomitted to avoid overlapping descriptions. In addition, a multilayerceramic capacitor will be described as an example of a multilayerelectronic component, but an embodiment thereof the present disclosuremay be applied to various electronic products, for example, an inductor,a piezoelectric element, a varistor, a thermistor, and the like, usingthe above-described dielectric composition.

In the body 110, the dielectric layer 111 and the internal electrodes121 and 122 are alternately stacked.

Although the specific shape of the body 110 is not particularly limited,as illustrated, the body 110 may be formed to have a hexahedral shape orthe like. Due to the shrinkage of the ceramic powder contained in thebody 110 during a firing process, the body 110 may have a substantiallyhexahedral shape but not a hexahedral shape having a perfect straightline.

The body 110 may have first and second surfaces 1 and 2 opposing eachother in a first direction (a Z direction), third and fourth surfaces 3and 4 connected to the first and second surfaces 1 and 2 and opposingeach other in a second direction (an X direction), and fifth and sixthsurfaces 5 and 6 connected to the first and second surfaces 1 and 2,connected to the third and fourth surfaces 3 and 4, and opposing eachother in a third direction (a Y direction).

The plurality of dielectric layers 111 forming the body 110 are in afired state, and adjacent dielectric layers 111 may be integrated tosuch an extent that it is difficult to identify the boundariestherebetween without using a scanning electron microscope (SEM).

The dielectric layer 111 may be formed using the dielectric compositiondescribed above.

As the dielectric layer 111 is formed using the above-describeddielectric composition, the dielectric layer 111 may include a pluralityof grains, and the plurality of grains may have an average grain size of50 nm or more and 500 nm or less.

If the average grain size is less than 50 nm, there may be problems suchas a decrease in dielectric constant, and insufficient implementation ofexpected effects against a lack of solid solution of additive elements,based on a decrease in grain growth rate, may occur. If the averagegrain size exceeds 500 nm, there is a concern that the rate of change ofcapacitance depending on the temperature and DC voltage may increase,and reliability may decrease due to a decrease in the number ofdielectric grains per dielectric layer.

In addition, at least one or more of the plurality of crystal grains mayhave a core-shell structure.

As at least one of the plurality of crystal grains has a core-shellstructure, the dielectric constant and the reliability may beeffectively improved.

On the other hand, the body 110 may include first internal electrode 121and second internal electrode 122 disposed inside the body 110 anddisposed to face each other with the dielectric layer 111 interposedtherebetween, to form a capacitance forming portion A, and coverportions 112 and 113 formed on the upper and lower portions of thecapacitance forming portion A.

The capacitance forming portion A is a portion contributing to thecapacitance formation of the capacitor, and may be formed by repeatedlystacking the plurality of first and second internal electrodes 121 and122 with the dielectric layer 111 therebetween.

Upper cover portion 112 and lower cover portion 113 may be formed bystacking a single dielectric layer or two or more dielectric layers onthe upper and lower surfaces of the capacitance forming portion A in athickness direction, respectively, and basically serve to prevent damageto the internal electrode due to physical or chemical stress.

The upper cover portion 112 and the lower cover portion 113 may notinclude an internal electrode, and may include the same material as thatof the dielectric layer 111.

For example, the upper cover portion 112 and the lower cover portion 113may include a ceramic material, for example, may include a bariumtitanate (BaTiO₃)-based ceramic material.

Margin portions 114 and 115 may be disposed on side surfaces of thecapacitance forming portion A.

The margin portions (114 and 115) include a margin portion 114 disposedon the sixth side 6 of the body 110 and a margin portion 115 disposed onthe fifth surface 5 of the body 110. For example, the margin portions114 and 115 may be disposed on both side surfaces of the ceramic body110 in the width direction.

As illustrated in FIG. 3, the margin portions 114 and 115 may indicateareas between both ends of the first and second internal electrodes 121and 122 and boundary surfaces of the body 110, in a cross section of thebody 110 in the width-thickness (WT) direction.

The margin portions 114 and 115 may basically serve to prevent damage tothe internal electrode due to physical or chemical stress.

The margin portions 114 and 115 may be formed by applying a conductivepaste to a ceramic green sheet except a place in which the marginportions are to be formed to form internal electrodes.

In addition, to suppress the step difference caused by the internalelectrodes 121 and 122, after the internal electrodes 121 and 122 arestacked, the internal electrodes are cut to be exposed to the fifth andsixth surfaces 5 and 6 of the body, and then, a single dielectric layeror two or more dielectric layers may also be laminated on both sides ofthe capacitance forming portion A in the width direction, therebyforming the margin portions 114 and 115.

The internal electrodes 121 and 122 are alternately stacked with thedielectric layer 111.

The internal electrodes (121 and 122) may include first and secondinternal electrodes 121 and 122. The first and second internalelectrodes 121 and 122 are alternately disposed to face each other withthe dielectric layer 111 constituting the body 110, interposedtherebetween, and may be exposed to the third and fourth surfaces 3 and4 of the body 110, respectively.

Referring to FIG. 2, the first internal electrode 121 is spaced apartfrom the fourth surface 4 and exposed through the third surface 3, andthe second internal electrode 122 is spaced apart from the third surface3 and exposed through the fourth surface 4.

In this case, the first and second internal electrodes 121 and 122 maybe electrically separated from each other by the dielectric layer 111interposed therebetween.

Referring to FIG. 3, the body 110 may be formed by alternately stackinga ceramic green sheet on which the first internal electrode 121 isprinted and a ceramic green sheet on which the second internal electrode122 is printed, and then firing the same. The material for forming theinternal electrodes 121 and 122 is not particularly limited, and amaterial having excellent electrical conductivity may be used.

For example, the conductive paste for internal electrodes containing atleast one of palladium (Pd), nickel (Ni), copper (Cu) and alloys thereofmay be printed on a ceramic green sheet, thereby forming the internalelectrode.

As the printing method of the conductive paste for the internalelectrode, a screen-printing method or a gravure printing method may beused, but an embodiment thereof is not limited thereto.

On the other hand, to obtain miniaturization and high capacity of themultilayer ceramic capacitor, the thicknesses of the dielectric layerand the internal electrode should be relatively reduced to increase thenumber of stacked layers. As the thicknesses of the dielectric layer andthe internal electrode are relatively reduced, the reliability may belowered, and characteristics of insulation resistance and breakdownvoltage may be lowered.

Therefore, as the thicknesses of the dielectric layer and the internalelectrode are further reduced, the effect of improving reliabilityaccording to an embodiment of the present disclosure may be increased.

In detail, according to an embodiment of the present disclosure, bycontrolling the correlation between the rare earth element content, thevariable valence acceptor element and fixed valence acceptor elementcontents, Ba and Ca contents contained in the dielectric composition,the insulation resistance may be improved, and the dielectric constantper grain size may be improved. Therefore, insulation resistance anddielectric constant per grain size may be significantly improved when athickness te of the internal electrodes 121 and 122 or a thickness td ofthe dielectric layer 111 is 0.41 μm or less, according to an embodimentof the present disclosure.

The thickness te of the internal electrodes 121 and 122 may indicate anaverage thickness of the first and second internal electrodes 121 and122.

The thickness te of the internal electrodes 121 and 122 may be measuredby scanning an image of a third and first directional cross section L-Tof the body 110 with a scanning electron microscope (SEM).

For example, for any internal electrode 121, 122 extracted from an imageobtained by scanning the third and first directional cross-section (a WTcross-section) cut in the center of the body 110 in the second direction(the L direction), with the SEM; the thicknesses thereof may be measuredat 30 equidistant points in the third direction, to measure an averagevalue.

The thirty equidistant points may be measured in the capacitance formingportion A indicating an area in which the internal electrodes 121 and122 overlap each other.

The thickness td of the dielectric layer 111 may indicate an averagethickness of the dielectric layer 111 disposed between the first andsecond internal electrodes 121 and 122.

Similar to the thickness te of the internal electrode, the thickness tdof the dielectric layer 111 may also be measured by scanning the thirdand first directional cross-section (the LT cross-section) of the body110 with a scanning electron microscope (SEM).

For example, for any dielectric layer 111 extracted from an imageobtained by scanning the third and first directional cross-section (a WTcross-section) cut in the center of the body 110 in the second direction(the L direction), with the SEM; the thickness thereof may be measuredat 30 equidistant points in the third direction, to measure an averagevalue.

The thirty equidistant points may be measured in the capacitance formingportion A indicating an area in which the internal electrodes 121 and122 overlap each other.

Although the thicknesses of the cover portions 112 and 113 are notparticularly limited, the thickness tp of the cover portions 112 and 113may be 20 nm or less, to facilitate miniaturization and relatively highcapacity of the multilayer electronic component.

The external electrodes 131 and 132 are disposed on the body 110 and areconnected to the internal electrodes 121 and 122.

As illustrated in FIG. 2, the multilayer electronic component 100 mayinclude the first and second external electrodes 131 and 132 disposed onthe third and fourth surfaces 3 and 4 of the body 110, respectively, andconnected to the first and second internal electrodes 121 and 122,respectively.

In this embodiment, although a structure in which the multilayerelectronic component 100 has two external electrodes 131 and 132 isdescribed, the number, shape and the like of the external electrodes 131and 132 may be changed depending on the shapes of the internalelectrodes 121 and 122 or other uses.

The external electrodes 131 and 132 may be formed using any material aslong as the material has electrical conductivity such as a metal, and adetailed material thereof may be determined in consideration ofelectrical characteristics, structural stability, and the like. Theexternal electrodes 131 and 132 may have a multilayer structure.

For example, the external electrodes 131 and 132 may include electrodelayers 131 a and 132 a disposed on the body 110 and plating layers 131 band 132 b formed on the electrode layers 131 a and 132 a.

As a more detailed example of the electrode layers 131 a and 132 a, theelectrode layers 131 a and 132 a may be sintered electrodes including aconductive metal and glass, or resin-based electrodes including aconductive metal and a resin.

In addition, the electrode layers 131 a and 132 a may have a form inwhich a sintered electrode and a resin-based electrode are sequentiallyformed on the body. The electrode layers 131 a and 132 a may be formedby transferring a sheet including a conductive metal on the body, or maybe formed by transferring a sheet including a conductive metal on asintered electrode.

As the conductive metal included in the electrode layers 131 a and 132a, a material having excellent electrical conductivity may be used andis not particularly limited. For example, the conductive metal may beone or more of nickel (Ni), copper (Cu) and alloys thereof.

As a more detailed example of the plating layers 131 b and 132 b, theplating layers 131 b and 132 b may be an Ni plating layer or an Snplating layer, and may have a form in which the Ni plating layer and theSn plating layer are sequentially formed on the electrode layers 131 aand 132 a. The Sn plating layer, the Ni plating layer, and the Snplating layer may be formed sequentially. In addition, the platinglayers 131 b and 132 b may include a plurality of Ni plating layersand/or a plurality of Sn plating layers.

The size of the multilayer electronic component 100 is not particularlylimited.

For example, to obtain miniaturization and high capacity at the sametime, the thickness of the dielectric layer and the internal electrodeshould be relatively reduced to increase the number of stacked layers.Thus, the reliability and insulation resistance may be more improved inthe multilayer electronic component having a size of 0603 (length×width,0.6 mm×0.3 mm) or less.

Therefore, when the distance between the third and fourth surfaces ofthe body is defined as L and the distance between the fifth and sixthsurfaces is defined as W, L may be 0.6 mm or less, and W may be 0.3 mmor less. For example, the multilayer electronic component 100 may be amultilayer electronic component having a size of 0603 (length×width, 0.6mm×0.3 mm) or less.

Embodiment

In an embodiment of the present disclosure, a main additive is added tothe barium titanate (BaTiO₃) powder of the 100 nm level as a maincomponent to satisfy the following Table 1, a binder and an organicsolvent such as ethanol are added and are wet mixed to prepare adielectric slurry, and then, the dielectric slurry is applied and driedon a carrier film to prepare a ceramic green sheet, thereby forming adielectric layer.

In this embodiment, the ceramic green sheet was prepared by mixing aceramic powder, a binder, and a solvent to prepare a slurry, and theslurry was manufactured into a sheet having a thickness of 1.0 μm orless, using a doctor blade method.

Next, a conductive paste for internal electrodes including 40 to 50parts by weight of nickel powder with an average particle size of 0.1 to0.2 μm was prepared.

After forming the internal electrode by applying the conductive pastefor the internal electrode on the green sheet by the screen-printingmethod, a laminate was formed by laminating the green sheet on which theinternal electrode pattern is formed to about 0.3 mm thickness, andthen, the laminate was pressed and cut into the 0603 size (length×width,0.6 mm×0.3 mm).

Thereafter, the cut laminate was heated to 400° C. or lower under anitrogen atmosphere to remove the binder, and then fired at a firingtemperature of 1200° C. or lower and a hydrogen concentration of 0.5% H₂or lower, followed by measuring a grain size, a dielectric constant pergrain size, and insulation resistance (IR), and the measurement resultsare described in Table 1 below.

The grain size was obtained by measuring the average grain size byimaging a cross section, and the dielectric constant and insulationresistance per grain size were measured at 1 kHz, AC 0.5 V using an LCRmeter.

The dielectric constant per grain size is indicated by ⊚ when thedielectric constant per grain size is 3600 or more as an excellent case,by ○ when it is good by 3100 to 3500, by Δ when it is normal by 2600 to3000, and by X when it is poor by 2500 or less.

The insulation resistance is indicated by ⊚ when insulation resistanceis 10⁷mΩ or more as an excellent case, by ○ when it is good by 10⁵mΩ ormore and less than 10⁷mΩ, by Δ when it is normal by 10⁴mΩ or more andless than 10⁵mΩ, and by X when it is poor by less than 10⁴mΩ.

TABLE 1 (DT/AT)/ Dielectric Constant per Insulation No La/DT (Ba + Ca)Grain Size Grain Size Resistance 1 0.10 0.5 X 310 nm X 2 0.25 X 310 nm X3 0.50 Δ 305 nm Δ 4 0.75 Δ 298 nm Δ 5 1.00 Δ 305 nm X 6 0.10 1 ◯ 320 nmΔ 7 0.25 ◯ 326 nm ◯ 8 0.50 ◯ 330 nm ⊚ 9 0.75 ◯ 342 nm ⊚ 10 1.00 ⊚ 326 nmX 11 0.10 2 ◯ 340 nm ◯ 12 0.25 ◯ 342 nm ⊚ 13 0.50 ◯ 329 nm ⊚ 14 0.75 ⊚330 nm ◯ 15 1.00 ⊚ 332 nm X 16 0.10 3 ◯ 330 nm ◯ 17 0.25 ◯ 322 nm ⊚ 180.50 ⊚ 320 nm ⊚ 19 0.75 ⊚ 324 nm ◯ 20 1.00 ⊚ 315 nm X 21 0.10 4 ◯ 370 nm◯ 22 0.25 ⊚ 362 nm ⊚ 23 0.50 ⊚ 360 nm ◯ 24 0.75 ⊚ 368 nm Δ 25 1.00 ⊚ 354nm X 26 0.10 5 ⊚ 480 nm ◯ 27 0.25 ⊚ 468 nm ◯ 28 0.50 ⊚ 460 nm ◯ 29 0.75⊚ 425 nm Δ 30 1.00 ⊚ 408 nm X 31 0.10 6 ⊚ 588 nm X 32 0.25 ⊚ 560 nm X 330.50 ⊚ 540 nm X 34 0.75 ⊚ 552 nm X 35 1.00 ⊚ 520 nm X

In the case of Test Nos. 1 to 5 in which (DT/AT)/(Ba+Ca) was 0.5, thedielectric constant per grain size and insulation resistance wereevaluated as being normal or poor.

In the case of Test Nos. 31 to 35 in which (DT/AT)/(Ba+Ca) was 6, allwere evaluated as having poor insulation resistance. In addition, allhad a dielectric grain size of more than 500 nm, and there is a concernthat the capacity change rate depending on a temperature and a DCvoltage may increase. Further, in the case of thinning the dielectriclayer, there is a fear that the reliability may decrease due to thedecrease in the number of dielectric grains per dielectric layer.

Therefore, it can be confirmed that there is a need to adjust(DT/AT)/(Ba+Ca) to be more than 0.5 and less than 6.0.

In addition, it can be seen that the dielectric constant per grain sizeincreases as the content ratio of the lanthanum (La) to the sum (DT) ofthe rare earth element contents is increased.

However, Test Nos. 5, 10, 15, 20, 25, 30 and 35 with La/DT of 1.0 wereall evaluated as having poor insulation resistance.

Therefore, it can be confirmed that the content ratio of the lanthanum(La) to the sum (DT) of rare earth element contents may be, in detail,0.1 or more and less than 1.0.

As set forth above, according to an embodiment, by controlling thecorrelation between the rare earth element content, the variable valenceacceptor element and fixed valence acceptor element contents, Ba and Cacontents contained in the dielectric composition, the insulationresistance may be improved, and the dielectric constant per grain sizemay be improved.

In addition, a dielectric composition, in which high dielectricproperties may be implemented without deterioration of reliability evenin a case in which the dielectric layer is thinned, and a capacityreduction rate depending on a DC voltage is not great, and a multilayerelectronic component including the same, may be provided.

While this disclosure includes detailed examples, it will be apparent toone of ordinary skill in the art that various changes in form anddetails may be made in these examples without departing from the spiritand scope of the claims and their equivalents. The examples describedherein are to be considered in a descriptive sense only, and not forpurposes of limitation. Descriptions of features or aspects in eachexample are to be considered as being applicable to similar features oraspects in other examples. Suitable results may be achieved if thedescribed techniques are performed to have a different order, and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner, and/or replaced or supplemented by othercomponents or their equivalents. Therefore, the scope of the disclosureis defined not by the detailed description, but by the claims and theirequivalents, and all variations within the scope of the claims and theirequivalents are to be construed as being included in the disclosure.

What is claimed is:
 1. A multilayer electronic component comprising: abody including a dielectric layer and an internal electrode; and anexternal electrode disposed on the body and connected to the internalelectrode, wherein the dielectric layer includes a dielectriccomposition, wherein the dielectric composition includes: one of BaTiO₃,(Ba,Ca)(Ti,Ca)O₃, (Ba,Ca)(Ti,Zr)O₃, Ba(Ti,Zr)O₃ and (Ba,Ca)(Ti,Sn)O₃, asa main component; a first subcomponent comprising a rare earth element;and a second subcomponent comprising at least one of a variable valenceacceptor element and a fixed valence acceptor element, and wherein thedielectric layer comprises a plurality of crystal grains, wherein one ormore of the plurality of crystal grains have a core-shell structure. 2.The multilayer electronic component of claim 1, when a sum of contentsof the rare earth element is defined as DT, and a sum of contents of thevariable valence acceptor element and the fixed valence acceptor elementis defined as AT, (DT/AT)/(Ba+Ca) satisfies more than 0.5 and less than6.0.
 3. The multilayer electronic component of claim 1, wherein the rareearth element comprises lanthanum (La), and further comprises at leastone of yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr),neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu),gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium(Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and a contentratio (La/DT) of the lanthanum (La) to a sum (DT) of the contents of therare earth element satisfies 0.1 or more and less than 1.0.
 4. Themultilayer electronic component of claim 1, wherein the firstsubcomponent comprises an oxide or carbonate containing the rare earthelement in a range from 0.2 mol to 4.0 mol relative to 100 mol of themain component.
 5. The multilayer electronic component of claim 1,wherein the variable valence acceptor element comprises at least one ofMn, V, Cr, Fe, Ni, Co, Cu and Zn, and the fixed valence acceptor elementcomprises at least one of Mg and Zr.
 6. The multilayer electroniccomponent of claim 1, wherein the second subcomponent comprises an oxideor carbonate containing at least one of a variable valence acceptorelement and a fixed valence acceptor element in a range from 0.01 mol to4.0 mol relative to 100 mol of the main component.
 7. The multilayerelectronic component of claim 1, wherein the dielectric compositioncomprises a third subcomponent, which is an oxide or carbonatecomprising Ba, wherein the third subcomponent is included in an amountin a range from 0.37 mol to 4.0 mol with respect to 100 mol of the maincomponent.
 8. The multilayer electronic component of claim 1, whereinthe dielectric composition comprises a fourth subcomponent which is atleast one of an oxide comprising at least one of Si and Al and a glasscompound comprising Si, wherein the fourth subcomponent is contained ina range from 0.5 mol to 7.0 mol with respect to 100 mol of the maincomponent.
 9. The multilayer electronic component of claim 1, whereinthe dielectric layer comprises a plurality of crystal grains, whereinthe plurality of crystal grains have an average grain size in a rangefrom 50 nm to 500 nm.
 10. The multilayer electronic component of claim1, wherein the dielectric layer has an average thickness of 0.41 μm orless.